大学毕业论文—包装工程.doc

包装工程毕业论文 大豆分离蛋白/羧甲基纤维素共混包装薄膜 的制备与性能研究 专业：包装工程 内容摘要：以羧甲基纤维素(CMC)和大豆蛋白(SPI)为原料，通过加入甘油采用共混的方法制备薄膜。羧甲基纤维素对共混薄膜的结构、热稳定性和机械强度都有一定的系统改进。通过红外光谱分析(FTIR)，可知：CMC和SPI发生美拉德反应，CMC中的-OH基团和SPI中的氨基团在升温成键过程中被消耗了，生成C=N键；通过XRD测试，可验证美拉德反应，随着CMC和甘油的增加会对SPI的结晶结构和结晶度构成破坏；通过机械性能测试，可知：无甘油时，CMC/SPI共混薄膜随CMC添加量的增加，薄膜的屈服应力和断裂应力相应增加，这是由于分子间交联的结果，且加入甘油后共混膜会变得更加柔软，机械力学性能增强；通过热失重(TGA)，可知：混合膜的热稳定性均比纯SPI粉末要高且随着CMC添加比例的升高，混合膜的热稳定性提高。结果证明，大豆蛋白共混羧甲基纤维素可以改善和提高膜的结构和性能。 Preparation and characterization of soy protein isolate / carboxymethyl cellulose blend films Abstract: Films based on carboxymethyl cellulose (CMC) and soy protein isolate (SPI) with compatibilized by glycerol were respectively prepared by a solution-casting method. The effects of CMC contents on the blend structure, thermal stability, as well as mechanical properties, were systematically investigated. FTIR results showed that Maillard reactions occurred between CMC and SPI, these result show that the –OH group in CMC and amino groups in SPI were consumed during the blending process at elevated temperature. Moreover, a new C=N was inducted. XRD curves indicated Maillard reactions had broken the crystalline of SPI, with the increasing of CMC and glycerol contents in blend films. For CMC/SPI samples without glycerol, the values of σy and σb increase with increasing CMC content, respectively, that because mechanical properties of the SPI blends depend on the crosslinking methodology and the blend becomes softer due to plasticization by glycerol, the mechanical prosperities had been improved. TGA curves indicated blend reaction could improve stability of SPI. With the increasing of CMC contents in blend films, the stability had been improved. These results showed that the structure and properties of SPI films were modified and improved by blending with CMC. Keywords: Carboxymethyl cellulose; Soy protein isolate; Maillard reactions; Blend 1 导言 食品包装，是食品科技领域的一个重要学科，主要是保存和保护所有类型的食品和它们的原材料免受氧化和微生物的腐蚀。来自于石油化